1. Field of the Invention
The present invention relates to a vehicle brake hydraulic pressure control unit.
2. Description of Related Art
Various types of vehicle brake hydraulic pressure control units have been proposed, and among them, for example, there are vehicle brake hydraulic pressure control units which are described in Japanese Patent Unexamined Publication JP-A-07-47945 and U.S. Patent Examined Publication U.S. Pat. No. 6,260,582 B1.
In a vehicle brake hydraulic pressure control unit described in the JP-A-07-47945, a flange having through holes is provided on a motor, and by inserting screws from the motor side through the through holes so as to be screwed into a base body, the motor is fixed to the base body. On the other hand, a flange having through holes is also provided on a control housing, and by inserting screws from the control housing side through the through holes so as to be screwed into the base body, the control housing is fixed to the base body.
In a vehicle brake hydraulic pressure control unit described in the U.S. Pat. No. 6,260,582 B1, through holes are formed on a flange of a motor, and through holes are also formed on a base body coaxially with the through holes of the motor flange, and by inserting screws from the motor side through the through holes of the motor and the through holes of the base body so as to be screwed into a control housing, the motor, base body and control housing are fixed together.
In the vehicle brake hydraulic pressure control unit disclosed in JP-A-07-47945, however, the flanges are provided on both the motor and the control housing to prevent the interference of heads of the screws and a mounting tool (for example, a screw driver) with the motor main body or the housing main body, and due to the flange being provided on the control housing which is a relatively large constituent member, the control housing is made larger in size. Because of this, the base body is also made large in size in a portion which corresponds to the flange, these leading to a problem that an increase in overall size of the vehicle brake pressure control unit.
In contrast to this, in the vehicle brake hydraulic pressure control unit disclosed in U.S. Pat. No. 6,260,582 B1, since the screws are screwed into the base body from a back surface of the control housing, the flange of the control housing does not have to be formed large, and hence, a reduction in size of the control housing can be attained, whereby a reduction in size of the vehicle brake hydraulic pressure control unit has been attained.
In this vehicle brake hydraulic pressure control unit, however, since the configuration is adopted in which the common screws are used to fasten the base body and the control housing together, when considering tolerances of the respective constituent members, the inside diameters of the through holes of the flange of the motor and the through holes of the base body need to be set larger than the outside diameter of the screws in advance, to which extent the base body and the flange of the motor are enlarged in size.
In addition, in the event that the respective through holes are increased due to the tolerances, a certain length of time is necessary to position the respective members in a radial direction, this deteriorating the assembling efficiency, and furthermore, there has been caused a problem that looseness is generated between the respective constituent members after they have been assembled together.